1. Field of the Invention
The present invention relates to a bobbin integrally formed with a winding coil, an actuator employing the bobbin, and a manufacturing method thereof, and more particularly, to a bobbin integrally formed with a winding coil using a printed circuit board technology to move the bobbin in a precise position in tracking and focusing directions, an actuator employing the bobbin, and a manufacturing method thereof.
2. Description of the Related Art
FIG. 1 is a conventional optical pickup device. As shown in FIG. 1, a general optical pickup device 10 is assembled with a main axle 3 and an auxiliary axle 5 provided on a deck panel 1 of an optical driver to reciprocate in an axis of the main axle 3 to reproduce a signal recorded on an optical disc D or record a signal on the optical disc D. The optical pickup device 10 includes a base 30 reciprocating along the axis together with the main axle 3 and the auxiliary axle 5, and an actuator disposed on the base 30 to move together with the base 30 so that an input optical beam is converged into a spot of the optical disc D.
FIG. 2 is a perspective view of an actuator 20 of the optical pickup device shown in FIG. 1. As shown in FIG. 2, the actuator 20 includes a bobbin 22 having an objective lens and focusing and tracking coils 23 and 24 of a copper wire to minutely and precisely move the objective lens in a focusing direction, e.g., an upward or downward direction, as well as a tracking direction, e.g., a left or right direction. A magnetic unit 27 and a yoke 28 are disposed around the bobbin to generate an electromagnetic field.
The bobbin 22 is elastically supported to a holder 26 through a wire 25 horizontally extended in the tracking direction. That is, one end of the wire 25 is coupled to the bobbin 22 by soldering, and the other end of the wire 25 is fixed to the holder 26. Therefore, the bobbin can minutely move in the upward, downward, left, and right directions using an elastic force of the wire 25.
The actuator 20 moves the objective lens 21 in the focusing and tracking directions according to an electromagnetic force generating when power is supplied to the respective focus and tracking coils 23 and 24 through the wire 25.
A conventional actuator module having the winding coil uses a conventional technology, such as a Lorentz force, to move the bobbin, and a principle, e.g., the Lorentz force, can be used in the winding coil. When current flows through the winding coil made of the copper wire, the Lorentz force is generated according to an influence of the magnetic field of a permanent magnetic unit disposed in front of the winding coil so that the bobbin is moved in the upward, downward, left, and right directions. A plurality of winding coils are disposed adjacent to the permanent magnet unit to control and adjust upward, downward, left, and right movements of the bobbin.
As industry is highly developed, electronic products are minimized in size, and an actuator used with a thinner and smaller product is produced according to user demands. In the conventional actuator module, since the winding coil is wound to be disposed adjacent to the bobbin, and the winding coil is required to have a predetermined size to obtain a necessary sensitivity, it is impossible to minimize the electronic product in size. Moreover, when a number of parts are assembled, it is disadvantages in that a manufacturing process becomes complicated, and that a defect ratio of the electronic product increases.
Furthermore, it is an advantage in that in the conventional winding coil, the copper wire of the winding coil can be easily cut off. When the permanent magnet unit includes a number of complicated divided magnets according to the arrangement of the coils so as to reduce a volume of the bobbin, the manufacturing costs of the permanent magnet unit increase, and a very difficult technology is required to produce the bobbin.